Warning: Warning: there are two 'XXXXX' files | "_config.php" nowhere to be found

where a /db/build of a site returns a laundry list of something along the lines of:

Warning: Warning: there are two 'AssetAdmin' files: '/kunden/homepages/0/d214712168/htdocs/cms/code/AssetAdmin.php' and '/kunden/homepages/0/d214712168/htdocs/./cms/code/AssetAdmin.php'. This might mean that the wrong code is being used. in /homepages/0/d214712168/htdocs/sapphire/core/ManifestBuilder.php on line 136

The solution mentions a simple problem with a _config.php file in the tutorial that needs to be disabled in the tutorial folder. I can't find it in my installed site, I checked the silverstripe-v2.0.2b.tar.gz file for it and I've searched a local installation for the file, and cannot find this file.